If I under Window 7 enable it ( PreventScrollbarCrash=1), then the first time in a session when I use Lister, I see the little Lister window in the upper left corner where the final window is going to be showed - this is the same as I see under Window 8.1.

So it seems that the function can be enabled manually, even when not needed (Windows 7), and also be disabled manually (PreventScrollbarCrash=0) under Windows 8.1, if you are not haunted by the bug, and don't want to see the extra Lister window. If I dont set the parameter under windows 8.1 it defaults to 1, and it defaults to 0 under windows 7.

1) It depends, and explaining it there would be too extensive.
2) TC has to open a hidden Lister window (and keep it open) to prevent the crash. This lister window has to be visible for a short moment, otherwise it has no effect.

2ghisler(Author)
2) I meant, describe it in the help, not here, so that other users could find this information without having to search for this specifit topic on your forum (which they don't know exists, in the first place).

2ghisler(Author)
If a normal user starts seeing unexpected blinking Lister windows it's definitely something he might want to change, and there must be information at his disposal about why this happens, what needs to be done to avoid it, and what the caveats are. Right now, he has nothing of this sort, so he cannot make a correct decision. He has to go and search the official forum for the answer (and what if he has no Internet at the moment?), and read the long thread, instead of being provided a simple one-sentence explanation in the help file.

You considered this an important enough issue to dedicate a special key for handling it. In my opinion, if it deserves an option, it certainly deserves an explanation what this option does.

PreventScrollbarCrash=0/1 - defaults to 1 on Windows 8.1, otherwise defaults to 0. Opens an extra Lister window the first time Lister is used in a session. The window is made invisible after loading of the main Lister window - this is to prevent a potential crash in Lister under Windows 8.1 when opening Lister several times fast after each other.

I agree that such a help is required, otherwise it is not clear at all why this option exists (because no one usually wants to unfix a bug) and which side effects it may cause. petermad's help makes it clear what this option does, when it should be used and why anyone may want to disable it.